Quantitative analysis of anthocyanins in Euterpe oleracea (acai) dietary supplement raw materials and capsules by Q-TOF liquid chromatography/mass spectrometry

Context: Euterpe oleracea Mart. (Arecaceae) fruits and their dietary supplements are gaining much popularity internationally. Anthocyanins and their aglycons are responsible for the dense color of a a fruit and are associated with a wide spectrum of health promoting effects. Objective: Quantitative analysis of anthocyanins in a a dietary supplement raw materials; processed a a powder (ADSR-1), organic a a powder (ADSR-2), and nonorganic a a powder (ADSR-3) by quadrupole-time-of-flight liquid chromatography/mass spectrometry (Q-TOF LC/MS) have been reported in this study. Materials and methods: The chromatographic separation for anthocyanins was achieved using a C-18 column with a gradient of 0.1% formic acid in water and 0.1% formic acid in methanol and acetonitrile (50: 50, v/v). MS and MS/MS experiments were carried out on an electrospray ionization-Q-TOF LC/MS. Results: Except for ASDR-2, all the a a samples were found to have cyanidin 3-glucoside (1), cyanidin 3-sambubioside (2), cyanidin 3-rutinoside (3), and peonidin 3-rutinoside (4). ASDR-2 contained anthocyanins 1 and 3. Among the a a samples quantified, ADSR-3 showed higher concentration of anthocyanins compared to other raw materials and capsules tested in this study. Discussion and conclusion: The anthocyanins 1-4 present in ADSR-3 were 27.13 +/- 0.37, 1.76 +/- 0.04, 31.07 +/- 0.49, and 3.46 +/- 0.08 mg/100 g dry wt, respectively. The LOQ values for anthocyanins 1-4 were in the range of 2.44-9.76 ng/mL. Accuracy of the method was assessed by performing a recovery experiments. The intraday and interday variations (RSDs) were <10%. This is the first report on quantitation of anthocyanins in a a dietary supplement raw materials and capsules.